<div id="viewer-container"></div>
<script>
  let viewer = undefined
  function initViewer() {
    viewer = new DC.Viewer('viewer-container')
    let baselayer = DC.ImageryLayerFactory.createGoogleImageryLayer({
      style: 'img'
    })
    baselayer.defaultAlpha = 1 //透明度 0~1
    baselayer.defaultBrightness = 2 //亮度 1为界点
    baselayer.defaultContrast = 1 //对比度  1为界点
    baselayer.defaultGamma = undefined //伽马强度
    baselayer.defaultSaturation = undefined // 饱和度
    viewer.addBaseLayer(baselayer, {
      iconUrl: 'examples/images/icon/img.png',
      name: '地图'
    })
  }
  DC.ready(initViewer)
</script>
